/**
* Function: inner
* @param int $screenid - The id of the screen you wish to load
*
* This function differs from the index function in that this function, that is
* /screen/inner is called by the inner IFRAME.
*/
public function inner($screenid)
{
//If no parameter, redirect somewhere else
if (!isset($screenid)) {
redirect('/');
}
// Load the screen model
$this->load->model('screen_model');
$screen = new Screen_model();
//Load variables of screen model type
$screen->load_model($screenid);
$data['id'] = $screenid;
// Check for sleep mode to determine the view. If the screen is asleep,
// just use the default three_col. If the screen should be awake, set up
// a $data variable and set the numcols to the number of columns and the
// zoom level to the custom zoom level.
if ($screen->is_asleep()) {
$data['numcols'] = 3;
$data['template'] = 'three_col';
} else {
$data['numcols'] = $screen->get_num_columns();
$data['zoom'] = $screen->zoom;
}
// Call the screen_template view and pass the $data variable. Each
// element of the $data array will become a variable, i.e. $data['id'] will
// become $id in the views
$this->load->view('includes/screen_template', $data);
}
/**
* Function: json
* @param int $screen_id - The id of the screen whose updates you need to load
*
* This is one of the biggest and most complicated functions in the application.
* It generates the JSON data update for every screen. More specifically, it
* loads a screen, ensures that it should be awake at this moment, and gets all
* the blocks. For each block it finds the agency-stop pairs and calls the
* appropriate APIs to get the real-time transit data. It assembles all this
* information, including the custom block data and the CaBi status and prints
* it all out as one JSON response.
*/
public function json($screen_id)
{
// Load the Update model and the screen model
$this->load->model('update_model');
$update = new Update_model();
$this->load->model('screen_model');
$screen = new Screen_model();
// Fill this variable with the screen values.
$screendata = $this->screen_model->get_screen_values($screen_id, true);
//Load variable of screen model type
$screen->load_model($screen_id);
// We will collect all the data to publish via JSON in the $update variable,
// so set a few of its static properties based on the screendata variable.
$update->screen_name = $screendata['settings'][0]->name;
$update->screen_version = $screendata['settings'][0]->screen_version;
$wmata_key = $screendata['settings'][0]->wmata_key;
// Update the last_checkin value for this screen. This allows us to ensure
// that our screens are regularly calling for updates.
$this->_update_timestamp($screen_id);
// If the screen should be asleep right now, print that in JSON and do not
// bother to load any real-time data.
if ($screen->is_asleep()) {
$update->sleep = true;
print json_encode($update);
} else {
//Gather all the necessary data into the $update variable
//and then output the variable as JSON
// This helper contains the fuctions that call the various agency APIs
$this->load->helper('transit_functions');
// Obviously this screen should be awake.
$update->sleep = false;
$stopname = '';
// For every block... (remember that one block can contain more than one
// stop or CaBi station!)
foreach ($screendata['blocks'] as $block) {
$stops = $block->stop;
//Set up (or clear) variables to handle the various data
$vehicles = array();
unset($bike);
$bikes = array();
unset($override);
// For each of the agency-stop pairs for this block...
foreach ($stops as $stop) {
// ... get the arrival predictions for each agency.
// Collected the line exclusions for this block
$exclusions = array();
if (isset($stop['exclusions'])) {
$exclusions = explode(',', $stop['exclusions']);
}
// For this agency-stop pair, check to see what mode it is and then
// call the approriate API function.
switch ($this->_get_agency_type($stop['agency'])) {
case 'bus':
$newset = array();
// Get the bus prediction data back. This get_bus_predictions
// function covers ART, WMATA, DC Circulator, Prince George's TheBus and Shuttle UM
$set = get_bus_predictions($stop['stop_id'], $wmata_key, $stop['agency']);
if (isset($set[0])) {
// Loop through the results. If the bus line is not in the
// exclusions array, add it to a new set. We will abandon the
// excluded lines.
foreach ($set as $b) {
if (!in_array(strtoupper($b['route']), $exclusions)) {
$newset[] = $b;
}
}
$vehicles[] = $newset;
}
break;
case 'subway':
// Get predictions from WMATA for rail station with id $stop['stop_id').
$vehicles[] = get_rail_predictions($stop['stop_id'], $wmata_key);
break;
case 'cabi':
// For each bike station, get the status. Notice that the data
// will be put into the $bikes array since each block may have
// multiple CaBi stations.
$bikes[] = get_cabi_status($stop['stop_id']);
break;
case 'custom':
// This is where the custom block data goes. There is no clean up.
$override = $block->custom_body;
break;
}
}
// Combine the different agency predictions for this stop
// into a single array and sort by time. Make sure you have actual
// predictions first!
if (count($vehicles) > 0) {
if ($this->_get_agency_type($stop['agency']) == 'bus') {
// Combine multi-agency data for buses, then combine same routes
$stopdata = combine_agencies($vehicles);
$stopdata = $this->_combine_duplicates($stopdata);
} elseif ($this->_get_agency_type($stop['agency']) == 'subway') {
// Combine same routes data for subway
$stopdata = $vehicles[0];
$stopdata = $this->_combine_duplicates($stopdata);
} else {
$stopdata = $vehicles[0];
}
// If there is a limit to the number of arrival lines to list
// at any bus stop, remove the extra vehicles from the array
if (isset($block->limit) && isset($stopdata) && count($stopdata) > $block->limit && $block->limit > 0) {
array_splice($stopdata, $block->limit);
}
// Set the stop name to the API stop name that comes first. WMATA and
// ART will have different descriptions for the same stop, but we will
// just use the first name instead. You can override this with a
// custom stop name in the backend, of course.
if (isset($vehicles[0][0]['stop_name'])) {
$stopname = $vehicles[0][0]['stop_name'];
}
}
// If we're working with CaBi here
if (isset($bike)) {
$stopdata = $bike;
$stopname = $bike['stop_name'];
}
// Set the stop's custom name
if (strlen(trim($block->custom_name)) > 0) {
$stopname = $block->custom_name;
}
// If we're working with bikes, put all the relevant block data into
// an array. Otherwise, do the same for a bus or Metro block.
if (isset($bikes) && count($bikes) > 0) {
$stopdata = array('id' => $block->id, 'name' => clean_destination($stopname), 'type' => $this->_get_agency_type($stop['agency']), 'column' => (int) $block->column, 'order' => (int) $block->position, 'stations' => $bikes);
} else {
$stopdata = array('id' => $block->id, 'name' => clean_destination($stopname), 'type' => $this->_get_agency_type($stop['agency']), 'column' => (int) $block->column, 'order' => (int) $block->position, 'vehicles' => $stopdata);
}
// If this block is a custom block, put in the data here.
if (isset($override)) {
$stopdata = array('id' => $block->id, 'name' => clean_destination($stopname), 'type' => $this->_get_agency_type($stop['agency']), 'column' => (int) $block->column, 'order' => (int) $block->position, 'custom_body' => $override);
}
// Add all the stop data for this block to the stops array in the $update
// variable.
$update->stops[] = $stopdata;
}
// Print out the entire $update variable encoded as JSON
print json_encode($update);
}
}
